Ammonia pumping system for gas-type machine for developing photosensitive sheets



March 1, 1960 F. G. WILDE 2,926,592

AMMONIA PUMPING SYSTEMFOR GAS-TYPE MACHINE FOR DEVELOPING PHOTOSENSITIVE SHEETS Filed Jan. 19, 1956 2 Sheets-Sheet 1 I l I l ATTORNEY March 1, 1960 F. e. WlLDE 2,926,592

AMMONIA PUMPING SYSTEM FOR GAS-TYPE MACHINE FOR DEVELOPING PHOTOSENSITIVE SHEETS 2 Sheets-Sheet 2 Filed Jan. 19, 1956 INVEN-TOR. FREDERIGKG WILDE} BY 3 Z ATTORNEY AMMONIA PUMPING SYSTEM FOR GAS-TYPE MACHINE FOR DEVELOPING PHOTOSENSI- TIVE SHEETS Frederick G. Wilde, Rochester, N.Y., assignor to Paragon- Revolute Corporation, Rochester, N.Y., a corporation of New" York Application January 19, 1956, Serial No. 560,212

2 Claims. (Cl. 95-89) The present invention relates to a machine for developing photosensitive sheets by means of ammonia gas and the like. In a more specific aspect, the present invention relates to mechanism for pumping ammonia in solution to an evaporating tray in which the water solution of ammonia is evaporated to gas.

In conventional developing machines of the character described, the photosensitive sheet, after being exposed, is fed across one wall of the developing chamber in which the ammonia gas is generated. This wall is provided with openings through which the ammonia gas has access tothe exposed photosensitive sheetto develop the sheet. In the exposure chamber there is mounted an evaporating tray, into which water solution of ammonia is pumped; this tray is heated to evaporate the ammonia to generate the ammonia gas required for development.

Heretofore, it has been common practice to employ a diaphragm type pump to pump the water solution of ammonia from a convenient source of supply into the evaporating tray. Difficulties are not infrequently experienced with conventional pump installations, however.

ammonia. With full strength ammonia it is possible to increase the developing speed. Furthermore, it is not necessary for the user of the machine to go to the trouble of diluting the ammonia, which he buys at full strength, to the degree he thinks expedient.

Of course, if a gravity feed system is used in the machine for the ammonia in solution, it is not necessary to dilute the ammonia; but such a system also has its drawbacks; for instance, in regard to the size of the supply tank for the ammonia in solution, and with regard to the change in rateof discharge from the tank into the evaporating tray with change in liquid level in the tank, etc.

atent One object of the present invention is to provide an improved pumping system for machines of the character described which'will avoid the possibility of formation of vapors in the pump body, and which will, therefore, insure uniform delivery of the ammonia in solution to the evaporating tray regardless of temperature of the machine.

Another object of the invention is to provide a pumping mechanism for a machine of the character described with which full strength water solution of ammonia can be used, thereby eliminating the necessity for diluting the ammonia, and thereby, also speeding up development of the photosensitive sheets.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims. 1 r

In the drawings:

Fig, 1 is a fragmentary vertical section through a machine for developing photosensitive sheets by means of ammonia gas, showing the developing chamber and fragmentarily a portion of the drive to one form of pumping system constructed according to the present invention;

Fig. 2 is a fragmentary side elevation on an enlarged scale showing details of the pumping system;

Fig. 3 is a fragmentary 'side elevation, with parts broken away, looking at right angles to the view of Fig. 2;

Fig. 4 is a diagram illustrating the operation of the pump mechanism of Figs. 2 and 3; and

Fig. 5 is a fragmentary view, with parts broken away, showing an alternative form of pump mechanism constructed according to the present invention.

Referring now to the drawings by numerals of reference, and first to the embodiment of the invention illustrated in Figs. 1 to'4 inclusive, 10 denotes the framework of the base of the developing machine. On this frame work is mounted a cabinet 11, in which there is inclosed a developing chamber C. Mounted in chamber C is a shallow, V-shaped evaporating tray 12 which may be of conventional construction.

The developing chamber C is completely closed'on three sides. Its fourth side is closed by a series of paral-' as the photosensitive sheet is fed over the rollers by an endless, impervious belt 15. This belt passes around the driven roller 17 and over the guide roller 18; and it overlaps the edges of the developing chamber to close and seal the same.

The water solution of ammonia is supplied to the tray 12 by pumping mechanism constructed according to the present invention, and is vevaporated by any suitable means, such as the electric heating element 16.

In one embodiment of the invention the pump, which is denoted as a whole at 20 (Figs. 2, 3 and 4), is mounted directly in the sealed supply tank 22 which is adapted to hold ammonia in solution and which is disposed in the base of the machine. The pump is mounted at the bottom of this supply tank 22 to be fully submerged in'the water solution of ammonia.

The pump is adapted to be actuated in time with the movement of the endless belt by a cam or crank plate 24 which carries a pin 25. The crank plate 24 is driven by sprockets 26, 27, and a chain 28 in time with the roller 17 which drives the impervious belt 15.

As the cam or crank plate 24 rotates, the pin 25 engages the lever 30. This lever is pivoted at one end by means of a pivot pin 31 in the machine, and is constantly urged upwardly by a coiled spring 32 that is connected at one end by means ofpin 33 with the free end of the lever. The opposite end of spring32 is secured by means of pin 34 to cabinet 11. The lever 30 is connected intermediate its ends by means of a pin 35 with the plunger rod 36.0f the pump. As the cam plate 24 rotates, the plunger rod 36 will be reciprocated to suck the ammonia in solution from the tank 22 into the pump.

The chamber 41 is completely closed so that air will not enter it. The chamber 41 is connected by piping '42 with a second completely closed pressure chamber 44. A conventional check valve 45 is mounted in the piping 42 to prevent backflow of the liquid from the pressure chamber 44 into the pressure chamber 41.

' Tubing 46, which is connected with the bottom of pressure chamber 44, delivers the water solution of ammonia into the evaporating tray 12 in the developing chamber C. A conventional check valve 47 is provided in the tubing 46, to prevent backfiow of the solution into the pressure chamber 44, or passage of air into that chamber, and also tolcontrol the rate of flow of the solution to the evaporating tray. Any ammonia vaporsiformed in the supply tank 22 or 'in other parts of the system are forced out of the supply tank 22 .by the downward, gravity pressure of the liquid in the pressure chambers through the vent tubing 49 into the developing chamber C.

Because the liquid in the supply tank will keep the pump cool, the chances of vapors being formed in the system are minimized, as compared with the conventional systems where the heat generated by the pump in its operation lends itself to formation of vapors in the system. Furthermore, with the system of the present invention, on account of the head, resulting from the submersion of the pump body ,in the supply tank 22, and from the disposition of the pressure chamber 44 at a height above the pressure chamber 41, and from the disposition of the pressure chamber 41 at a height above the supply tank 22, vapors cannot form in the pump body. If any vapors form in the piping, these vapors are forced out by increase in pressure in the pressure vessels 41 and 44. Hence, with a pumping system constructed as described, there will be no compression of vapors without discharge of liquid into the evaporating tray. Moreover, there will be substantially uniform delivery of the water solution of ammonia to the evaporating tray.

"Instead of using a separate ammonia supply tank it maybe convenient to use the bottle, in which the ammonia itself is delivered, as theammonia supply tank of the machine. The user of the machine can then just substitute a new bottle when one bottle is empty. Such use is illustrated in Fig. 5. Here 50 denotes the bottle,

'or carboy, in which the water solution of ammonia is shipped. This bottle, or carboy, is simply placed in the base of the machine. Mounted on it is a saddle member '52 which is shaped to seat on the rounded upper end of the'bottle, and which has an opening that surrounds the neck of the bottle. The bottle is closed by a cork or plug 53 which has an opening through it to receive the tube 54. Mounted to reciprocate in this tube is e p np nse The plunger' 55 is tubular. Secured to its lower end is a plug or guide member 56 on which is threaded the nipple 57, which is provided with a seat for the ball check valve 58. This member 57 has a bore 60 which communicates with the bore of the tubular plunger 55. A pin '59, which is secured in the member 57, limits upward movement of the check valve 58. Members 56 and 57 guide theplunger 55 in its reciprocation in tube 54.

Mounted directly in the tubular member 54 adjacent the lower end thereof is a 'plug 65, which provides ayseat for the ball checlevalve '66. This member is formed with a bore 67 which communicates with the tubular member 54. A pin 68 secured in the member 65 limits upward movement of theball check valve 66. The tubular member 54 communicates at its lower end with the bottle or carboy 50 close to the bottom of the bottle or carboy; and the lower end of the'tubularmember 54 may be slotted out, as denoted at 79 to permit ready flow of the liquid from the bottle or carboy into the tubular member.

In this embodiment of the invention, the plunger 55 is actuated by a lever 75lwhieh is pivotallyconnected at 76 with the armature or plunger 77 of a solenoid 80. The solenoid is mounted on the saddle 52.

The lever is connected at one end by pin 78 and slots 79 with plunger 55. The lever 75 is pivotally mounted by means of a pin 81 on a bracket 82 which is secured to the saddle 52. The lever is constantly urged in a clockwise direction about its pivot 81 by a coil spring 83 which is connected at one end by means of pin 84 with the lever 75 and which is connected at its other end to a clip 85 which is secured in a bracket 87 that is fastened in any suitable manner to the saddle 52.

When the solenoid 80 is energized, the plunger .77 is pulled downwardly against the resistance of the coil spring 83, forcing the plunger 55 downwardly in the tube 54. The downward movement of the plunger causes the valve 53 to open, and closes the valve 66. Thus, the liquid between the valves 66 and 58 is pumped up through the tubularplunger 55,

When the solenoid is deenergized, the spring 83 returns the parts to the positions shown in Fig. 5, sucking the check valve 66 open and causing the check valve 58 to be closed. Thus, liquid is sucked into the portion 88 of the tubular member 54 between the check valves 66 and 58, Thus the portion 88 constitutes a supply chamber for the ammonia in solution.

The water solution of ammonia may be delivered by tubing 90 to a pressure chamber 41, and thence through piping 42 to a pressure chamber 44, and thence through piping 46 to an evaporating tray 12 as shown in Fig. 4.

A vent tube 92 is mounted in an opening in the plug or cork 53, and is connected by tubing, such as tubing 49, to the developing chamber C to deliver into that chamber any vapors formed in the system. The head of liquid in the pressure chambers 41 and 44 forces this vapor out of the bottle or carboy 50.

The solenoid is preferably operated in time with the movement of the endless belt 15. For this purpose, the camplate 24 may be used through pin 25 to close periodically a switch that closes the circuit to the solenoid 80. This may be a normally open switch, which will open when the pin 25, in the rotation of the plate 24, releases the switch.

The amount of stroke of the lever 75 may be regulated by adjustment of the stop screw 94 which threads into the bracket 95. Bracket 95 is secured to the bracket ,82.

Again, because the pump is submerged in the ammonia bottle, it will be kept cool, and the head of liquid in the bottle will prevent formation of vapors in the pump body; while the air-tight pressure chambers, located as they are above tank 50, will operate to force out of the system any vapors formed in the piping. Therefore, there will be uniform delivery of the water solution of ammonia to the evaporating tray.

While difierent embodiments of thejinvention have been described, it will be understood that the invention is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in theart to which the invention pertains, and asmay he applied to the essentialfeatures.hereinbefore set forth,'.and as fall within the scope of the invention orthe limits of the appended claims.

Having thus described my invention, what I claim is:

1. An ammonia supply system for a print developing machine having a developing chamber, an evaporating tray in said chamber for evaporating ammonia from liquid solution into ammonia gas, said chamber having an exposure area through which a photosensitive sheet can be exposed to said gas, and means for advancing a photosensitive sheet over said exposure area, said supply system comprising a tank .for the supply of ammonia in solution, said tank beingdisposed at a lower level than said evaporating tray, a pump submerged in saidltank and having its inlet submerged in said tank also to provide a head of liquid above said inlet, a closed pressure chamber disposed at a lower level than said evaporating tray but at a higher level than said tank, said closed pressure chamber having an inlet and an outlet and being adapted to be filled with ammonia in solution, said outlet being adjacent to the bottom of said pressure chamber and below said evaporating tray whereby said outlet is under a head of liquid in said chamber, means connecting the outlet of said pump with the inlet of said closed pressure chamber, means connecting the outlet of said closed pressure chamber with said evaporating tray to dispense said ammonia solution to said tr-ay under positive pressure, and means for actuating said pump whereby said pump serves to elevate said ammonia solution from said tank to said closed pressure chamber and thence to said evaporating tray under positive pressure, the heads of liquid in said supply system serving to limit formation of vapors therein.

2. An ammonia supply system for a print developing machine having a developing chamber, an evaporating tray in said chamber for evaporating a water solution of ammonia into ammonia gas, said chamber having an exposure area through which a photosensitive sheet can be exposed to said gas, and means for advancing a photosensitive sheet over said exposure area, said supply system comprising a tank for the supply of ammonia in solution, said tank being disposed at a lower level than said evaporating tray, a pump submerged in said tank and having its inlet submerged in said tank also to provide a head of liquid above said inlet, a closed pressure chamber disposed at a lower level than said evaporating tray but at a higher level than said tank, said closed pressure chamber having an inlet and an outlet, said outlet being at the bottom of said closed pressure chamber and below said evaporating tray whereby said outlet is under the head of liquid in said chamber, means connecting the outlet of said pump with the inlet of said closed pressure chamber, means including piping for connecting the outlet of said closed pressure chamber with said evaporating tray to dispense said ammonia solution to said tray under positive pressure, a check valve in said piping to prevent back flow of liquid from said tray into said closed pressure chamber, means for venting gases formed in said tank into said developing chamber, and means for actuating said pump whereby said pump serves to elevate said ammonia solution from said tank to said closed pressure chamber andthence to said evaporating tray under positive pressure, the heads of liquid in said supply system serving to limit formation of vapors in said supply system and to force vapors out of the supply system.

References Cited in the file of this patent UNITED STATES PATENTS 1,904,551 Smith Apr. 18, 1933 2,096,015 Von Meister et a1 Oct. 19, 1937 2,265,613 Richards Dec. 9, 1941 2,475,809 Sullivan et a1. July 12, 1949 2,553,543 Bodine May 22, 1951 2,583,678 Wilde Jan. 29, 1952 2,675,758 Hughes Apr. 20, 1954 2,696,771 Frantz Dec. 14, 1954 FOREIGN PATENTS 115,003 Sweden Sept. 18, 1945 686,990 Great Britain Feb. 4, 1953 

